TIMBUKTU, Mali (AP) — A United Nations expert mission has found that more than 4,000 ancient manuscripts out of a total collection of 46,000 stored in the northern Mali city of Timbuktu were destroyed by Islamic radicals during their ten-month occupation of the city.

The experts also have identified additional mausoleums that were damaged during the occupation, raising the total to 16, said David Stehl, program specialist in the cultural section of UNESCO, the U.N. body that added Timbuktu’s monuments to its list of World Heritage sites in 1988.

Along with the rest of northern Mali, Timbuktu was occupied by al-Qaida-linked fighters following a military coup in March 2012. The extremists were driven out following a French military campaign in January, but not before burning the manuscripts they could get their hands on.